The proposed research activities are designed to enhance and expand the functions of The Department of Epidemiology at The University of Texas System Cancer Center, M.D. Anderson Hospital & Tumor Institute; specifically those activities related to preparation for data sharing among the nation's Comprehensive Cancer Centers. Specific activities include: 1) the extension of follow-up efforts to improve current methods and to develop new approaches; 2) the development of a rapid update capability to facilitate interactive patient file maintenance; 3) the extension of current quality control procedures to include an increasing proportion of the data base and the development of additional quality control procedures; 4) the development of data sharing capabilities to assure conformity of collected data items and computer file interfaces.